Field of the Invention
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.
Description of the Related Art
At present, an electrophotographic photosensitive member containing an organic photoconductive material (organic electrophotographic photosensitive member, hereinafter sometimes referred to as “photosensitive member”) is in the mainstream of an electrophotographic photosensitive member to be mounted on a process cartridge or an electrophotographic apparatus. The electrophotographic photosensitive member using the organic photoconductive material has advantages, such as a pollution-free property, high productivity, and the ease of material design.
The electrophotographic photosensitive member generally includes a support and a photosensitive layer formed on the support. In addition, the photosensitive layer is generally a laminated photosensitive layer obtained by laminating a charge generating layer and a hole transporting layer in the stated order from a support side. Further, to cope with a problem with an image failure, such as fogging, an undercoat layer is often arranged between the support and the photosensitive layer for suppressing the injection of charge from the support side to a photosensitive layer side to suppress a reduction in charging ability.
In addition, in recent years, a charge generating material having higher sensitivity has been used. However, a rise in sensitivity of the charge generating material involves the following problem. The quantity of charge to be generated increases, and hence the charge is liable to remain in the charge generating layer and a ghost is liable to occur. Specifically, the so-called positive ghost phenomenon in which the density of only a portion irradiated with light at the time of a forward rotation in an output image increases is liable to occur. A technology involving incorporating an electron transporting material into the undercoat layer to smoothen the transfer of an electron from a charge generating layer side to the support side has been known as a technology of suppressing such remaining of the charge in the charge generating layer.
In each of, for example, Japanese Patent Application Laid-Open No. 2001-83726, Japanese Patent Application Laid-Open No. 2003-345044, and Japanese Patent Application Laid-Open No. 2008-65173, as a technology involving incorporating the electron transporting material into the undercoat layer or a layer that can correspond to the undercoat layer, there is a disclosure of a technology involving incorporating the electron transporting material, such as a fluorenone compound derivative, an imide compound derivative, or an anthraquinone derivative, into the undercoat layer. In addition, in each of Japanese Patent Application Laid-Open No. H05-27469 and Japanese Patent Application Laid-Open No. H05-134443, there is a disclosure of a technology involving incorporating a naphthalenetetracarboxylic diimide compound or a benzenetetracarboxylic diimide compound represented by a specific general formula into an intermediate layer (that can correspond to the undercoat layer).